1. Field of the Invention
The present invention relates to a control apparatus for controlling a plurality of electrical devices in a time division multiplex system. More particularly, it relates to a central processing apparatus for centrally processing signals from a plurality of the electrical devices.
2. Description of the Prior Art
Time division multiplex systems and frequency multiplex system have been employed to transmit signals through small number of lines to a plurality of electrical devices. Time division multiplex systems have been employed particularly when the number of signals to be transmitted is large. Time division multiplex devices include various coding techniques such as PCM systems, PPM systems, etc. These systems have been conventionally used for communications, data transmissions etc. However, these systems are quite complicated and of high cost as they are designed to transmit high quality signals. The conventional systems are too complicated to be practical in transmitting simple data signals, such as ON-OFF signals of switches over relatively short communication distances such as in a ship, a train, a car, a factory, and the like.
It has accordingly been proposed to detect signals by transmitting a clock timing signal and data signals carrying the information of the electrical devices in 1 - 2 bits, transmitting the data signal in return and detecting the data signals by using the clock timing signals to detect predetermined addresses. The multiplex signals can be transmitted by this type of system in quite a simple manner relative to PCM or equivalent systems.